wpf-custom-window-snap

Test project in (.NET framework 4.8) WPF, including window with full windows snap support on custom caption buttons

If you don't want to manage all this features/issues by yourself, I recommend using ControlzEx or any other library. I've created this project as test for implementing these features to our legacy application, where I cannot simply change base classes and use any other library.

NOTE: While the Debugger is attached, the resize can be a bit flickery. When the debugger is detached everything is smooth

This project features code that enables this features, when using WindowStyle.None:

• using Windows Snap feature (automatically snap window to all sides of screen or maximizing/restoring the window)
  • this is done using the WindowChrome feature (available from .NET Framework 4.5)
  • also, when using the WindowChrome object, you don't need to use DragMove() and handle resizing by yourself anymore - it's all there
• using Windows Snap preview feature (Windows 11+)
  • this is done by identifying Maximize button in NCHITTEST (0x0084) message as HTMAXBUTTON
  • see file MainWindow.MaximizeSnap.cs
  • this code also includes fix for maximize button effects not being triggered (hover and press) by explicitly setting internal dependency properties
• the Maximize feature of WindowsStyle.None requires fixing window size and position
  • this is done by using the code in MainWindow.Fullscreen.cs
  • also, there is need to refresh WindowChrome and set ResizeBorderThickness to zero (disable resizing), as it partially breaks the ability to put the window back "down"

The code in this repo is mix of various sources:

• https://learn.microsoft.com/en-us/dotnet/api/system.windows.shell.windowchrome?view=netframework-4.8
• https://stackoverflow.com/questions/19280016/windowchrome-resizeborderthickness-issue
• https://stackoverflow.com/questions/69797178/support-windows-11-snap-layout-in-wpf-app
• dotnet/wpf#4825
• https://gitlab.com/jplibraries/windowsextensionlibrary/
• https://stackoverflow.com/questions/70976583/get-real-screen-resolution-using-win32-api - DPI per monitor handling
• and possibly some other places I've already forgot